help replacing 97 Honda Accord thermostat

[Mark44]

I've done thermostats before - no biggie. But this one is buried far back in the motor and when I got all done and was tightening up the cover ... bang, I cracked the thermostat case.

You can see in the diagram the piece I'm talking about. So I got it loose but it has a small hose/pipe going into the bottom of it and I can't hardly get to the case to get it loose from this pipe. Is this just a more force issue? Pull harder? Or is there a trick to getting the old thermostat case to turn loose of its friend?

All constructive (!) advice appreciated. It's the daughter's car - can't set it on fire and just leave it for the garbage man. And in this Texas heat it probably needs a cooling system!

[Luck_of_the_Draw]

If its a 4 cylinder the Housing bolts to the back of the motor with 2(maybe3) 10mm headed bolts. Pull those and it should come loose. The pipe it hooks to runs across the back of the motor to the water pump housing on the block. Once the thermostat housing is loose the only thing holding it together is big O Rings at each end and a couple of hoses. These O Rings are rarely re usable. It's all hard to get to so do yourself a favor and get 2 new O rings for the pipe so you don't have to do the job twice.

[Mark44]

If its a 4 cylinder the Housing bolts to the back of the motor with 2(maybe3) 10mm headed bolts. Pull those and it should come loose. The pipe it hooks to runs across the back of the motor to the water pump housing on the block. Once the thermostat housing is loose the only thing holding it together is big O Rings at each end and a couple of hoses. These O Rings are rarely re usable. It's all hard to get to so do yourself a favor and get 2 new O rings for the pipe so you don't have to do the job twice.

This is the voice of experience! Those are 10 mm bolts. So how'd you get the casing to let go of that hose or did you pull the hose out of the water pump? There don't seem to be any clamps or anything. Just an O ring. Do you just pull the hose and the casing apart?

Yes, it's a 4 cylinder.

[Luck_of_the_Draw]

It'll either come out of the block or the housing will come off. Either way its just O rings holding it in.


Not me, I know a guy.

Allen from Honda/Toyota Heaven gave me the advice.

[dessl]

I know a guy in Grand Prairie that works on them fairly cheap. Pm if you need his number.

[buzzcut]

If it's an aluminum tube its probably flared at the end and held tight to the housing by a brass fitting. I doubt its just "jammed in there" with rubber O rings holding it in/on. That wouldn't hold the high pressure the system is under. I'm guessing there is a hex head fitting on it.

[Mark44]

If it's an aluminum tube its probably flared at the end and held tight to the housing by a brass fitting. I doubt its just "jammed in there" with rubber O rings holding it in/on. That wouldn't hold the high pressure the system is under. I'm guessing there is a hex head fitting on it.

I need to know more about this. It feels kind of rubbery but it could just be greasy hands on an aluminum tube. Where would that fitting be and what would it look like? More details please.

[Mark44]

In the drawing above the "hose" (part #11) is designated as "pipe." that kinda makes me think it's an aluminum pipe. but notice there is no fitting shown there. it just sticks up in the thermostat casing.

I have the casing loose from the block. but it sure doesn't want to let go of it's friend "part #11 - pipe." I am wondering if I just force it - just pull till it comes loose or if there is something else to do here.

[buzzcut]

You cracked the T stat housing flange at #6 in the diagram? What does the # 11 pipe do? Where does the other end go? Looks like to the water pump. Maybe its a bypass until the water heats and t stat opens? The pipe seems to attach between the T stat housing and block. Get a small mirror and flashlite and see if you can see it better.

[dessl]

Mark

I sent you my buddies number.

[snakejake]

the pipe is just "jammed" in there. Its set into two peices that are mounted solidly, therefore there is nowhere for it to go. It is just a force issue, and do get both of the orings. get a good spray penetrant too.

[Mark44]

the pipe is just "jammed" in there. Its set into two peices that are mounted solidly, therefore there is nowhere for it to go. It is just a force issue, and do get both of the orings. get a good spray penetrant too.

WINNER WINNER!!!

It is just jammed in there. A little WD40 and a quick twist and out it came. Tomorrow morning I've got me a date with a new gasket, a new Tstat housing and some socket wrenches. Let's see if I can get her all back together.

Thanks everyone for the help!

[AJMag]

Make sure you get ANY old gunk off of all reusable parts. They do like to do stuff like that and just press fit things in to parts you wouldn't think. In that case it is more than likely a lot of the oxidation and crud making it hard to get back out. So needless to say if there's any crap left on it will leak. Plus don't crank down on those bolts or you'll end up getting another new housing. It doesn't take much tension at all to form plastic or aluminum housing on, just snug.

[buzzcut]

Wow,I never would have thought that system would create a tight/strong enough seal for the high pressure in the water system but obviously the Honda design engineers know more than I do.

[Mark44]

Make sure you get ANY old gunk off of all reusable parts. They do like to do stuff like that and just press fit things in to parts you wouldn't think. In that case it is more than likely a lot of the oxidation and crud making it hard to get back out. So needless to say if there's any crap left on it will leak. Plus don't crank down on those bolts or you'll end up getting another new housing. It doesn't take much tension at all to form plastic or aluminum housing on, just snug.

hard to know when is snug and when it needs one more turn! that's waht got me this time.

how do I get all the corrosion etc off of there? suggestions?